If it were advertised at the time as a 1-year rental/subscription then it wouldn't be a rug pull. But the fact that it was advertised as a permanent purchase means that it is, no matter how long you got to use it before it was involuntarily taken back from you.
The article says "the purchase made in 2019 is not recognized anymore". The seller unilaterally taking back something you previously bought, especially without a refund, is a rug pull.
My Pro features still seem to be working for me. EDIT: No, I see now that Cloud Sync isn't a thing anymore. Looks like it's really lost its backend servers.
I mean it's beautifully presented, but why does it need to be so graphical?
(Thankfully in Firefox I can click the Reader view and it provides that)
A computer is meant to be programmed by the user. That is its raison d'être from the very beginning and why it is called like that.
Do you see how stupid that sounds?